In recent years, research and development of the smart board, which is composed by integration of a sensor and an actuator with a structure, have attracted much attention from various industries. Smart boards have been regarded as the targeted forms for research and development of various structural materials. Among the structural materials, a piezoelectric material has two effects: a positive piezoelectric effect, that converts mechanical input into electrical output, and a reverse piezoelectric effect, that converts electrical input into mechanical output. Research into embedding the piezoelectric material into a structure as a sensor or an actuator has been actively conducted. Research into embedding a piezoelectric material in a fibrous form into a composite material has been continued mainly at MIT in US, and also in Japan and other countries. This has been already utilized for skis and tennis rackets.
However, it is necessary to form an inter-digital electrode to drive a conventionally usable ceramic fiber, which disadvantageously increases cost. Further, if a conventional PZT-based piezoelectric material is used for the structure, the structure is disadvantageously hard and tends to crack, because of the properties in characteristic of ceramics. Although a structure that utilizes a polymer-type piezoelectric material is hardly confronted with the problem of cracking, the structure has a disadvantage in that the performance of the structure itself is inferior to that utilizing a PZT-based piezoelectric material.